State of the Art AM Introducing the Power Rock 828D/E from Rockwell -Collins

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1 State of the Art AM Introducing the Power Rock 828D/E from Rockwell -Collins

I The Power Rock SUPERIOR AUDIO PERFORMANCE DESIGNED WITH STEREO IN MIND EARN Modulation a.

modulation, demonstrates the excellent dynamic response of the Power Rock as indicated by the

Complete absence of any overshoot also shows the freedom -from -power -supply bounce, thanks

harmonic distortion, and intermodulation distortion, demonstrate the typical performance of

Both harmonic and intermodulation distortion readings were taken at 95% modulation, harmonic

2 I The Power Rock SUPERIOR AUDIO PERFORMANCE DESIGNED WITH STEREO IN MIND EARN Modulation a., This oscilloscope photograph, showing the output envelope under 20 Hertz square wave modulation, demonstrates the excellent dynamic response of the Power Rock as indicated by the near perfect square shape of the wave. Complete absence of any overshoot also shows the freedom -from -power -supply bounce, thanks to the Rockwell -Collins 12 phase supply These three photos, showing modulation, total harmonic distortion, and intermodulation distortion, demonstrate the typical performance of the Power Rock. Both harmonic and intermodulation distortion readings were taken at 95% modulation, harmonic distortion was taken at 1000Hz., while the intermodulation test follows the standard 4:1 SMPTE method. Harmonic._ ÿ I-' r r T.7=-=- o- á Intermodulation Viet., V With audio performance to please a most demanding audience. Rockwell -Collins 828 D /E -1 r I

I 'raking Its roots from a 1968 United States patent ( #3,413,5701 Issued to Collins Radio and Warren Bruene, the Rockwell -Collins Power Rock the direct result of years of research, development, and

S 2 TOTAL HARMONIC D 95% MODULAI c ú a 0 +1 AUDIO FREQUENCY I 95% MODULAI Modulation wave form showing effect of IPL 0 20 100 IPL settings on PWM card SwitchMod System'" -Far more than just a pulse

Instantaneous Peak Limiter and automatic modulation controller circuits to achieve dramatically improved AM audio performance, especially in the areas of low frequency response, intermodulation

reliability and efficiency The engineers at Collins set out to design an AM transmitter which would advance the state of the art in a number of areas, including audio performance, energy efficiency,

3 I 'raking Its roots from a 1968 United States patent ( #3,413,5701 Issued to Collins Radio and Warren Bruene, the Rockwell -Collins Power Rock the direct result of years of research, development, and refinement. S 2 TOTAL HARMONIC D 95% MODULAI c ú a 0 +1 AUDIO FREQUENCY I 95% MODULAI Modulation wave form showing effect of IPL IPL settings on PWM card SwitchMod System'" -Far more than just a pulse modulation circuit advancement, the Rockwell -Collins SwitchMod System combines the DC coupled series switching modulator with the stability of the proven 12 phase power supply and the built -in Instantaneous Peak Limiter and automatic modulation controller circuits to achieve dramatically improved AM audio performance, especially in the areas of low frequency response, intermodulation distortion and overall modulation density or loudness. The result is a louder, cleaner sound and improved 111. reliability and efficiency The engineers at Collins set out to design an AM transmitter which would advance the state of the art in a number of areas, including audio performance, energy efficiency, reliability, simplicity, size, and cost. To meet these goals, the 5000 W 828E -1 and its companion 2500W 828D -1 incorporate a number of features, some novel, some time proven, which, when combined in the Power Rock, make the most advanced transmitters in their class. IPL front panel adjustments set both positive and negative limits of modulation. Working in conjunction with the automatic modulation control, the maximum level of modulation is maintained at all power levels and with power line voltage variations of as much as 10 %. Below the limiting levels, audio performance is virtually ur lin pr. HI thi Tyl eff the an im tra ad rec 12 the err Po rec

The Power Rock' SUPERIOR AUDIO PERFORMANCE 'ARMONIC DISTORTION 5% MODULATION rreouency RESPONSE i% MODULATION 1K 10K le unaffected, while overmodulation due to power line variations or

- Using the high efficiency third harmonic injection technique of the proven Tyler -type PA, the Power Rock achieves final efficiency approaching 90 %.

This means a lower power bill in addition to lower cooling and air conditioning requirements to operate the Power Rock.

rectifiers to develop high voltage DC with a 720 Power Rock -front view Hertz ripple frequency This ripple is easily filtered without inductors, eliminating the power supply resonances

4 The Power Rock' SUPERIOR AUDIO PERFORMANCE 'ARMONIC DISTORTION 5% MODULATION rreouency RESPONSE i% MODULATION 1K 10K le unaffected, while overmodulation due to power line variations or audio peaks is effectively prevented. High Efficiency P.A. - Using the high efficiency third harmonic injection technique of the proven Tyler -type PA, the Power Rock achieves final efficiency approaching 90 %. This, combined with the high efficiency SwitchMod System, results in an overall efficiency in excess of 55 %, a vast improvement over the 42-45% in conventional transmitters. This means a lower power bill in addition to lower cooling and air conditioning requirements to operate the Power Rock. 12 -Phase Power Supply - Used by Collins since the early 1950's, the 12 phase power supply employes a combination Delta -Wye connected power transformer and two three -phase full wave rectifiers to develop high voltage DC with a 720 Power Rock -front view Hertz ripple frequency This ripple is easily filtered without inductors, eliminating the power supply resonances formerly associated with AM transmitters. Power supply sag and bounce are also eliminated. The result, again, is improved audio performance with better low frequency response and higher average modulation capability The absence of filter inductors and large capacitors, as well as the modulation transformer, also help make possible the reduction in size of the Power Rock and eliminates several expensive, failure -prone components.

High Efficiency "ljrler " PA circuit MIGM EFFlOEFKY WAVEFORM APPRO%(MATES A SOUARE WAVE the order of 4-6. Overall system 0, being the product of these, is approximately 250.

The Q -Taper network also has improved phase linearity over conventional networks, an important consideration for AM stereo.

skirts above and below the pass band. Unlike conventional "Pi" networks, the skirts of the Q -Taper network are nearly symmetrical with second harmonic supression at 80 db below carrier.

5 High Efficiency "ljrler " PA circuit MIGM EFFlOEFKY WAVEFORM APPRO%(MATES A SOUARE WAVE the order of 4-6. Overall system 0, being the product of these, is approximately 250. These lower circulating currents enable the use of smaller components without sacrifice in either performance or conservative component rating. The Q -Taper network also has improved phase linearity over conventional networks, an important consideration for AM stereo. Q -Taper Network" -The Rockwell -Collins Q -Taper output network, a proven performer in the 820D -1 and 820D -2 transmitters, provides Flatter response across the audio pass band and very steep skirts above and below the pass band. Unlike conventional "Pi" networks, the skirts of the Q -Taper network are nearly symmetrical with second harmonic supression at 80 db below carrier. The 3 db bandwidth is approximately 10% of the operating frequency or 1000KHz average. The 4 node network, whose overall Q is the product of the as of each node, achieves low circulating currents by the use of low nodal Q's, on Grounded Anode - By operating the anode of the final amplifier at DC ground, peak RF voltages are reduced to about half the peak value with respect to the chassis in conventional configuration, thus less possibility of arcing or corona. In addition, since the plate of the final is at DC ground, required metering of this stage can be done directly at ground reference, both local and remote. Finally, because the plate is at ground, there is no need to use a blocking capacitor or feed choke. This approach is made practical by the use of fiber optics to couple to the audio driver. DC coupling in the audio chain is thereby maintained throughout, for vastly improved audio performance.

$I brjarw uo\ofa o e,vaor ASS AND tdwnsslnl NETVOIR( REYONÇE Low/di NENbcoN / \ ENo/wüNE-AuClK 110 ]a Noip DlR rold NAsADNC RDONArpt Fiber Optics assembly Rear panel connections for$ Signal Access Card. Maintenance - Maintenance is an important consideration in any transmitter so the engineers at Rockwell -Collins have designed the Power Rock with service in mind.

Signal Access Card. Maintenance - Maintenance is an important consideration in any transmitter so the engineers at Rockwell -Collins have designed the Power Rock with service in mind.

The Power Rock uses the same tube type in both the final and the switch tube; spare tube stockage is minimized.

The Power Rock needs no screen supply due to the selection of triodes in both the final and switch tubes.

6 ASV Front Panel Q- Taper"" network circuit convnrrsonofeliei -.I brjarw uo\ofa o e,vaor ASS AND tdwnsslnl NETVOIR( REYONÇE Low/di NENbcoN / \ ENo/wüNE-AuClK 110 ]a Noip DlR rold NAsADNC RDONArpt Fiber Optics assembly Rear panel connections for Signal Access Card. Maintenance - Maintenance is an important consideration in any transmitter so the engineers at Rockwell -Collins have designed the Power Rock with service in mind. Modular circuit boards with an extender card and LED status indicators on major circuits and relays help simplify maintenance. The Power Rock uses the same tube type in both the final and the switch tube; spare tube stockage is minimized. And the Power Rock uses no tube sockets, eliminating yet another failure -prone component Yet, despite its size, the smallest 5 Kilowatt transmitter in the industry, accessibility is excellent. AM Stereo - The Signal Access Card, built into every Power Rock, provides rear panel access to both audio signal and RF drive, for use either in parallel operation of two Power Rocks or for possible later use in AM stereo. These terminals will make possible the connection of an external stereo generator to the RF drive line and to the audio chain, should this be required by future AM stereo systems. The Power Rock needs no screen supply due to the selection of triodes in both the final and switch tubes. Built -in forward and reflected power metering is standard, making possible quick checks of transmitter performance and checks for PWM card changes in antenna systems. Provision is made for the addition of an optional RF line current meter, and high /low power switching is standard. Audio feedback is taken from modulated DC rather than from the output envelope, reducing the sensitivity of the Power Rock''" to load conditions, while providing automatic power output control. And, though not recommended for repeated practice, when required. the Power Rock will come up to full power from a cold start in a matter of seconds at the push of a single button. The Power Rock - for louder, cleaner and better sound, higher efficiency, increased reliability lower operating costs, smaller size, and easier maintenance... for the ultimate in the AM art

*-3C ACPOWERINPIfT 30000CF) Collins nas set new standards for AM excellence 1. High efficiency SwitchMod `' pulse modulation technique. 2. High efficiency Tyler -type final. 3. Overall efficiency exceeding 55% at carrier.

Feedback taken from modulated DC, not from RF envelope for reduced sensitivity to load conditions. 7.

7 WE INVITE COMPARISON. 3CX3000FT DUAL CRYSTAL OSOiLLArOR DC6Af FEEDflACt DRNER I -0 HIGH EFFICIENCY PA 3510 OW PASS FILIER flanorass (LiTI'UT NETWORK SOIN MOOS,RATEO OC RE ROWER METER OUTPUT 500 ASCCW az IIIIIII SWI CH MOO *-3C ACPOWERINPIfT 30000CF) Collins nas set new standards for AM excellence 1. High efficiency SwitchMod `' pulse modulation technique. 2. High efficiency Tyler -type final. 3. Overall efficiency exceeding 55% at carrier. 4. Harmonic distortion less than 2.0% from 20 to 10000Hz. 5. Low intermodulation distortion per standard 4:1 SMPTE. 6. Feedback taken from modulated DC, not from RF envelope for reduced sensitivity to load conditions. 7. Bandpass "O- Taper" output network for flatter response across the audio pass -band and improved adjacent signal rejection. 8. Freedom -from-power-supply bounce and sag due to the dependable Rockwell- Collins 12 Phase supply 9. Lower RF peak voltages as a result of operations of the PA anode at DC ground. 10. Local and remote metering directly at ground reference. 11 No plate blocking capacitor or feed choke required. 12. Automatic modulation control keeps average level of modulation constant at all power levels and with a ± 10% line voltage variation, standard. 13. Built -in Instantaneous Peak Limiter, standard % modulation capability, standard. 15. Built -in Forward /Reflected Power meter, standard. We invite comparison. 16. Low power setting continuously adjustable over entire power range of the transmitter, standard. 17. Built -in trouble- shooting aids, standard. 18. Modular construction with extender card for easier maintenance. 19. No tube sockets for higher reliability 20. Using only one tube type for lower spares stockage costs. 21. Use of triodes eliminates need for screen grid supply 22. Overload recycle interrupts pulse train to remove high voltage in microseconds. After third overload, high voltage power supply is shut down, standard. 23. Signal Access Card for direct connection to RF and audio drive. 24. Improved phase linearity in "O-Taper" network for AM stereo. 25. Fully contained in a single bay cabinet, 33 " x 34-1/2" x 69" (7.9 sq. ft.). 26. Backed by the Rockwell -Collins two year limited parts warranty. 27. Supported by the Collins Broadcast Field Service Engineering team providing 24 -hour emergency technical assistance 365 days a year. 28. Further supported by emergency parts service available 24 hours, year- round. 29. Competitive pricing... see your Collins Broadcast team for full details.

RF Output Power 500-5500 w (250-2750 W) Output Impedance 50 Ohm nominal

7/8" EIA flange or stud output also available.

Carrier Amplitude Reg. 2% max. adjustable to 0 Frequency Stability 5 Hz.

range (below) Power Requirements 200-250 VAC 3 (6 3 or 4 wire, wye or

Better than 57% at 5000 Watts, 95% sine wave modulation.

@ 95% modulation, 5000 Watts output Total Harmonic Distortion less than 2

@ 95% mod, 5000 Watts output Noise better than -60dB reference 400 Hz.

ohms for 100% modulation Modulation Capability -100 %, + 125% standard

8 1-5/8" SPECIFICATIONS 828E-11828D-1) ELECTRICAL Frequency Range KHz. RF Output Power w ( W) Output Impedance 50 Ohm nominal (others available on special order) Output Fitting EIA male flange standard 7/8" EIA flange or stud output also available. Harmonic and Spurious Complies with FCC and CCIR regulations. Carrier Amplitude Reg. 2% max. adjustable to 0 Frequency Stability 5 Hz. over ambient temp. range (below) Power Requirements VAC 3 (6 3 or 4 wire, wye or closed delta, 50/60 Hz VAC available on special order Power Consumption %PF for 5000 Watts, 95% sine wave modulation Overall Efficiency Better than 57% at 5000 Watts, 95% sine wave modulation. Frequency Response 1 db, % modulation, 5000 Watts output Total Harmonic Distortion less than 2 % % mod, 5000 Watts output Noise better than -60dB reference 400 Hz., for 100% 5000 Watts output Audio Input + IO dbm 2db 600/150 ohms for 100% modulation Modulation Capability -100 %, + 125% standard GENERAL Size 88 cm. (34-3/4 ") W. x85 cm /8 ") D. x 176 cm. (69 ") H sq. meters (7.9 sq. ft.) floor space Weight 476 Kg (1050 lbs) Tubes 3CX3000F7 (2) Alr Flow Requirement 500 CFM Humidity 95 %, max Ambient Temp. Range To 0 C to + 50 C. (meets FCC requirements to -20 C) Altitude M (7,500 ft.) above mean sea level For further information, contact your local Collins Broadcast sales representative, or call Broadcast Products Marketing ,, Rockwell International Collins Transmission Systems Division Broadcast Products printed In USA

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